Encode or decode message bodies with base64. The e-mail protocol and user agents can not handle binary data. Therefore, binary data -but even sometimes non-binary data- is encoded into ASCII, this is transportable.

Base64 re-groups the bits of bytes, and maps them on characters. The data contains bytes of 8 bits (an octet). These are repacked into groups of 6 bits, pointing in an array of characters containing [A-Za-z0-9+/]. This way, three data bytes become 4 base64 bytes. The encoded data will be trailed by '=' characters to align on four bytes.

Fatal error: the specific package (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package.